Method of and apparatus for separating cre or metal of high specific gravity



July 4? 1933. c. T. RAUscHENBUscl-u ET AL ly9756 METHOD OF AND APPARATUS FOR SEPARATING ORE OR METAL OF HIGH SPECIFIC GRAVITY Filed Nov. 6, 1951 TTEY Patented July 4, 1933 CARL THEODOR RAUSCHENBUSCH ,PATENT OFFICE AND FELIX RAUSCHENBUSCH, OF KIRCHEN-ON-THE- SIEG, GERMANY METHOD 0F AND APPARATUS FOR SEPARATING CRE OR' METAL OF HIGH SPECIFIC GRAVITY Application iled November 6, 1931, Serial No. 573,508, and in Germany November 7, 1930.

Our invention relates to improvements in the method of and apparatus for separating ore or metal of high specific gravity from earth or comminuted ore, and the object of the improvements is to provide a method and an apparatus by means of which ,mineral or metal such as precious metal of high specific gravity is separated from ore or earth in which the heavy particles are contained 1n a state of finest distribution. Another object of the improvements is to provide a method and an apparatus by means of which the said heavy particles are completely separated from the other particles, and by means of which the heavy particles are obtained 1n separate deposits. Another object of the improvements is to provide a process in whlch the heavy particles are in contact only withl the water or other liquid used for separating the same, and in which they are not brought in contact with the air. Thereby a loss of heavy material is avoided which is caused by the said heavy material floating on the surface of the water when it is in a state of finest subdivision, and when it is brought in contact with the air. Other objects of the improvements will appear 4from the following description.

Forthe purpose of explaining the invention an apparatus suitable for putting the method into e'ect has-been illustrated in a diagrammatic way in the single figure of the accompanying' drawing, in which the said apparatus is shown in sectional elevation.

In the construction shown in the drawing the apparatus is particularly suitable for use in laboratories for ascertaining the relative amount of valuable matter in comminuted particles.

As shown in the figure, the apparatus comprises a receptacle A which ta ers from its top downwardly, and which ends at its bottom in a tubular portion C of small. diameter. Between the tapering portion A and the tubular portion C there is a glass-cock B. The tubular portion C is connected by a U-shaped portion F with a supply pipe E through which a suitable flushing liquid such as water is supplied to the bottom part of the receptacle A, the portions C, F and E being connected with each other by rubber tubes H. The supply pipe E is connected either to the main or to a water tank disposed at a high level above the receptacle A, the supply of the Water from the bottom of the said tank being preferred because thereby any access of air to the water and to the matter to be separated is prevented. The supply of water to the apparatus is controlled by means of a cock K. The top end of the receptacle A is formed with a tubular stud Lin which an overflow pipe D is fitted by means of a stopper I, the said overfiow pipe having its end connected to a comparatively long rubber tube G. By providing the stopper I the pipe D and the tube G may be readily removed from the receptacle A. In the example shown in the drawing all the parts except the rubber tubes H and G and the stopper I are made from glass, so that the separating operation may be readily observed. The cross-sectional area of the bore b of the cock B is equal to the cross-sectional area of the tubular portion C, and the bore of the bottom end of the tapering receptacle A is equal in area to the said bore b. The inner diameters of the glass-pipes D, El and F and the rubber tubes Gr and I-I are alike, and they are larger than the inner diameter of the tubular portion C, the bore b and the bottom part of the receptacle A. When it is desired to use the apparatus the cocks K and B are opened and so much water is admitted to the apparatus that thewater within the receptacle A rises substantially to the level indicated by the line a, whereupon the cock K and thecock B are closed. By thus partly 'filling the receptacle A with water the air is from the beginning expelled from the supply pipe E, the collecting pipe F and the tubular portion C. Further, the apparatus cannot be obstructed when filling the material to be tested into the receptacle A.

About 250 grammes of the material to be tested, that is finely comminuted rock or earth, are stirred in water and filled into the receptacle A through the intake L thereof, whereupon the overflow pipe D is again fitted into the said intake.

Now simultaneously the water supply cock K and the. cock B of the receptacle A are opened, the pressure of the water being such that the material within the receptacle A is energetically flushed and stirred. Ordinarily a pressure of lf), atmosphere will be satisfactory. Thereby the time of the washinggoperation will be comparatively short. e ore the receptacle A has been filled with water,

,and the finest particles or slime begin to escape through the ove flow pipe D, the pressure of the water is re uced by partly closing the cock K, so that the finest particles of the valuable ore or metal cannot be carried away together withv the finest waste matter or slime. The pressure needed in the said operations depends on the size of the grains of the material, and it must be the smaller the liner the said grain is.

After a few minutes the matter within the receptacle A will be clear, so that only clear water flows through the overflow D. Now the first part of the opera-tion is finished, and the leparation of the particles of ore or metal e ns.

4or this purpose the flow of the water and the pressure thereof are reduced so far that .the material within the receptacle A sinks to the lowermost point of the said receptacle, while it is just held floating within the said receptacle above the bore b of the cock B by the continuously entering water.

Now the long rubber tube Gr is lifted above the top part of the whole apparatus. Thereby the head of water within the receptacle A and therefore the resistance opposed to the How of the water areincreased,becausethesuc tion caused by the water flowing downwardly within the tube Gr is eliminated. By the reduction of the flow of the water the particles before held by the flow of the water in the bottom part of the receptacle A and above the cock B are able to sink in opposition to the reduced flow of the water through the tubular portion C and into the collecting pipe F, where they are deposited by reason of the comparatively large cross-section of the said collecting pipe. lf now the rubber tube G is again lowered, the velocity of the water is` again increased, and the lighter particles are flushed from the pipe F upwardly and into the receptacle A, While the particles of higher specific gravity, such as gold, platinum and the' like, remain on the bottom of the collecting pipe F.

Thus the separation of the particles of ore is effected while the water continues to flow through the apparatus, and it is deposited because the cross-sectional area of the collecting pipe F is larger than that of the tubular portion C, which results in a reduced velocityof the water within the pipe F.

The upward and downward movement of the tube Gr may be repeated from 20 to 30 times, until a concentrated deposit is obtained within the collecting pipe F, which. deposit nemico this case only to a few centimeters. By the small variations of the head of the water and the velocity thereof a perfectly pure deposit is obtained in the pipe F. When this result is obtained the Vcock K and the cock B are tightly closed.

Now the collecting pipe F may be removed from the apparatus by loosening the rubber tubes H.. The concentrated matter is poured into a cup, the water is decanted,'and the concentrated matter is dried, whereupon it may be microscopically or chemically eX- amined.

The separation of the matter may be repeated until no particles of ore or metal are deposited within the collecting pipe, that is until all the heavier minerals, particles of ore or the like have been separated from the raw material. Finally the receptacle A is emptied through the cock B and the tubular portion C, whereupon the apparatus is ready for further use.

We wish it to be understood that we do not limit ourselves to the manner of producing the variation of pressure within the receptacle by the method described herein, and that other means may be used for this purpose. For example the pipe G or the overflow D may be provided with a throttling member. Further, a suction valve may be provided in the intake pipe E for periodically reducing the prEessure of the waterwithin the supply pipe lBy our improved method and apparatus the following advantages are obtained 1. The flushing and separation of the material is carried out in a single apparatus in a` continuous flow of water and while excluding the air, so that even particles of ore which may float on the surface of the water are not lost.

" 2. Separation is effected within a collecting pipe which may be readily closed and removed, and in which all the valuable matter is deposited. lf the raw material contains several minerals of different specific gravities the said minerals are separately collected.

3. The accuracy of the method is such that perfectly pure microscopic preparations or concentrated matter for chemical investigation are obtained. Therefore our improved system may be used not only for examining lfinely comminuted rock or earth, but it may also be used for examining strata. If rfoble metals are contained in the material to be investigated in a finely distributed and metallic state, even traces of the said metals may be detected. Therefore our improved system may be used for continuously testing ceptacle is 250 grammes, after 10 minutes'.

noble metal analyses, and it may be used in lieu thereof, because in case of material taken from the same deposit the amount of the matter deposited within the collecting pipe indicates the amount of noble metal contained in the ore. If the noble metal does not contain much ore, and it is found in a linely divided metallic state, it is possible after some experience to deliver exact estimates as to the actual content in noble metal.

4. By reason of the uninterrupted ow of water which is alternately more or less energetic, the separation within the receptacle is continued during the whole duration of the process, so that successively all the heavier,v

particles of ore-must pass into thecollectin pipe. by reason of the variations of the hea of water, where they are precipitated. Therefore the new apparatus operates with a high degree of uniformity.

5. An important advantage of theinvention resides in the fact that the separation of the particles of ore and the like may be completed within a very short period of time.n After the flushing of the raw material has been finished which requires more or less time according to the amount of the material l and the size of the grain, the separation vof Athe particles of ore may be rapidly completed. For example, if the material within thereabout 50% of all the valuablev ore maybe deposited within the collecting pipe. Ifthe amount is smaller, a much higher proportion of the material isfseparated within the same time.

6.*By constructing the whole apparatus from glass all the flushing and separating operations can be observed. Thev apparatus may be readily taken into operation whenever it is needed, .because only water is needed for carrying out the process. y

We claim: i

.1. Theherein described method of'separating metal or ore from a mixture of metal or ore and comminuted matter of` lower specic gravity, which consists insubjecting a quantity of the mixture to an upwardl directed current of a suitable liquid ofsuc velocity as to stir the .said mixture while maintaining the same at a predetermined point, and thereafter partially reducing the quantitative flow of the liquid at said pointv sufficiently. to permit the components of higher specific gravity to sink within the current of liquid in opposition to the fiowthereof,

2. The method described in claim 1, in which the quantitative flow of theliquid is several times and alternately reducedand'increased to elfect substantially complete separation. j

3. The herein described method of se arating comminuted substances ofdi erent 'to a region having a lesser flow rate than that at said first mentioned region.

4. The herein described method of se arating comminuted `substances of di erent specilic gravities which comprises subjecting a mixture ofthe substances to an upwardly directed current of liquid in an upwardly expanding zone, adjusting the vvelocity of said current until the mixture is suspended above the constricted part of said zone and then intermittently and alternately reducing the flow of the liquid until the components of higher :specific gravity settle through the constricted part of said zone into a second enlarged zone and increasing the flow to carry any lighter 'components settling in said second rone back into said first zone.

' 5. Anvapparatus for separating metal or ore-fromfcomminuted matter of lower specific gravity, comprising a receptacle which is open at itstop and bottom and which tapers from its top downwardly, means for closing said receptacle at its bottom, a horizontally extending stratif ing receptacle communicat-` mg with and o llarger cross-section than the bottom of said tapering receptacle, means for supplying a suitable liquid through said co1- lecting receptacle. in contact with material settled therein into said tapering receptacle,

Y, an overflow connected with the top part ofsaid tapering receptacle, and means for varying the ilow'of the liquid through said receptacles.

6. An apparatus for separating metal or ore from comminuted matter of lower specific ravity comprising a tapering receptacle havv ing a. restricted inlet at the bottom and an outlet at the top'v thereof, a flexible tube connected to said outlet, a U-shaped collecting receptacle communicating with the inlet of said'tapering receptacle and of larger ilow cross-.section than said inlet and means for supplying liquid under a predetermined steady hydrostatic head through said collecting receptacle to said tapering receptacle and contactingit with the material in said collecting receptacle.

In testimony whereof we hereunto aix our signatures.

CARI. THEODOR RAUSCHENBUSCH.

FELIX RAUSCHENBUSCH. 

